Over the new Pallant House show, Eileen Agar: An Eye for Collage, hangs a brooding cloud of injustice. Agar, who died in her nineties in 1991, is commonly seen as the victim of a double conspiracy, having been both a woman and a surrealist. Female painters have always had a hard time of it, while Surrealism with a capital S went into steep decline after the 1940s. The Surrealists were a gentlemen’s club to which ladies  Gala Dali, Nusch Eluard, Lee Miller  might be admitted as muses and helpmeets, but never as members. This has been the view long peddled by feminist critics such as Germaine Greer and Whitney Chadwick, and it has stuck…